<html>
    <head>
        <title>Testing getElementById with a try catch statement</title>
    </head>
    <body>
        <div id="foo">Some text</div>
        <script>
            try {
                document.getElementById(undefined);
                document.getElementsByClassName(undefined);
                document.getElementsByTagName(undefined);
                document.querySelector(undefined);
                
            } catch(err) {
                console.log('Error found: ' + err);
                throw new Error("I detect an error!");
            }

            document.getElementById('foo');
        </script>
    </body>
</html>